The FBI has issued a warning that al-Qaida could possibly use fuel tankers as weapons in attacks on New York, Los Angeles and Chicago prior to Sept. 19.
However, a disagreement has broken out about the reliability of the information gathered for the bulletin.
FBI officials have said that the warning is based on uncorroborated evidence, but still others insist that there is room for concern.
The Associated Press reported that the FBI said the notice was based on a single source of undetermined credibility and that the information had not yet been corroborated.
Other experts, however, said the warning was specific enough to warrant closer attention.
Randy Larsen, head of the Institute for Homeland Security, told CBS News that the warning is very specific and gives local law enforcement something to be on the lookout for.
The warning said the terrorists would seek to hijack gasoline or oxygen tankers and ram them into a gas station to cause a massive explosion.
The nation’s security threat level has not been changed. It remains at the yellow – “elevated” level.